docs: consistently indent .rst files with 2 spaces

2 spaces is the most common indentation width used in the docs; adjust
the rest for consistency.

Also change .editorconfig accordingly.

docs/user/site.rst

@@ -27,29 +27,25 @@ domain_seed
   mesh, but should be different for firmware that is not supposed to mesh with
   each other.
 
-    The recommended way to generate a value for a new site is:
-    ::
+  The recommended way to generate a value for a new site is::
 
     echo $(hexdump -v -n 32 -e '1/1 "%02x"' </dev/urandom)
 
 prefix4 \: optional
-    The IPv4 Subnet of your community mesh network in CIDR notation, e.g.
-    ::
+  The IPv4 Subnet of your community mesh network in CIDR notation, e.g. ::
 
     prefix4 = '10.111.111.0/18'
 
   Required if ``next_node.ip4`` is set.
 
 prefix6
-    The IPv6 subnet of your community mesh network, e.g.
-    ::
+  The IPv6 subnet of your community mesh network, e.g. ::
 
     prefix6 = 'fdca::ffee:babe:1::/64'
 
 node_prefix6
   The ipv6 prefix from which the unique IP-addresses for nodes are selected
-    in babel-based networks. This may overlap with prefix6. e.g.
-    ::
+  in babel-based networks. This may overlap with prefix6. e.g. ::
 
     node_prefix6 = 'fdca::ffee:babe:2::/64'
 
@@ -57,21 +53,18 @@ node_client_prefix6
   The ipv6 prefix from which the client-specific IP-address is calculated that
   is assigned to each node by l3roamd to allow efficient communication when 
   roaming. This is exclusively useful when running a routing mesh protocol
-    like babel. e.g.
-    ::
+  like babel. e.g. ::
 
     node_client_prefix6 = 'fdca::ffee:babe:3::/64'
 
 timezone
-    The timezone of your community live in, e.g.
-    ::
+  The timezone of your community live in, e.g. ::
 
     -- Europe/Berlin
     timezone = 'CET-1CEST,M3.5.0,M10.5.0/3'
 
 ntp_servers
-    List of NTP servers available in your community or used by your community, e.g.:
-    ::
+  List of NTP servers available in your community or used by your community, e.g.::
 
     ntp_servers = {'1.ntp.services.ffac','2.ntp.services.ffac'}
 
@@ -109,8 +102,7 @@ opkg \: optional
   - ``%GR`` is replaced by the Gluon release (as specified in ``site.mk``)
 
 regdom \: optional
-    The wireless regulatory domain responsible for your area, e.g.:
-    ::
+  The wireless regulatory domain responsible for your area, e.g. ::
 
     regdom = 'DE'
 
@@ -123,7 +115,6 @@ wifi24 \: optional
   time units (TU). A time unit is equivalent to 1024 µs.
   If not set, the default value of 100 TU (=102.4 ms) is used.
 
-
   There are currently two interface types available. You may choose to
   configure any subset of them:
 
@@ -158,6 +149,7 @@ wifi24 \: optional
   ``mesh`` also accepts an optional ``mcast_rate`` (kbit/s) parameter for
   setting the multicast bitrate. Increasing the default value of 1000 to something
   like 12000 is recommended.
+
   ::
 
     wifi24 = {
@@ -205,6 +197,7 @@ wifi5 \: optional
 
 next_node \: package
   Configuration of the local node feature of Gluon
+
   ::
 
     next_node = {